643916466437 has 4 divisors (see below), whose sum is σ = 650168082720. Its totient is φ = 637664850156.

The previous prime is 643916466433. The next prime is 643916466539. The reversal of 643916466437 is 734664619346.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 643916466437 - 2² = 643916466433 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (643916466433) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3125807987 + ... + 3125808192.

It is an arithmetic number, because the mean of its divisors is an integer number (162542020680).

Almost surely, 2^643916466437 is an apocalyptic number.

It is an amenable number.

643916466437 is a deficient number, since it is larger than the sum of its proper divisors (6251616283).

643916466437 is a wasteful number, since it uses less digits than its factorization.

643916466437 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6251616282.

The product of its digits is 47029248, while the sum is 59.

The spelling of 643916466437 in words is "six hundred forty-three billion, nine hundred sixteen million, four hundred sixty-six thousand, four hundred thirty-seven".